DMCC

The fuel pumps will not turn on. I have replaced the following items:
front tank fuel pump
HP fuel pump (on the frame)
fuel pump relay
EEC relay

There is 12v to the fuel pump relay & EEC relay as the wiring diagram indicates.
at the other terminals on the EEC relay I measure about 2.75 volts with the key on.

The Inertia switch & the fuel tank switch show continuity when tested.

What else should I check for? Someone mentioned the Throttle Position Sensor, would that keep the pumps from running?

DMcc

Just call me Sean

iTrader: (1)

Check the computer for codes, this thread will explain how:
https://www.f150forum.com/f10/how-retrieve-trouble-codes-obdi-10907/
Sounds like there may be a computer issue. The TPS won't keep the pumps from running.

Tony1993

check the fuseable link by the eec relay, theres a brown wire that comes out if it and goes to a little round plastic box about a inch or so away then goes into a red wire, in that box there is a splice and it becomes corroded and wont complete the circut for the fuel pump relay, they had alot of wiring problems to do with these relays, espetialy if the truck sits alot

5Rangers

Did you put a ground on the vip test connector? After you do that, check for volts at the pump connector, while your there check for ground. Let us know what you come up with.

Mario1

I just bought a 1987 Ford inline 6 with the double tank well I bought low...really low on gas on the way to get it gas I ran out of gas. I filled her up got back on the road but in third gear and truck started losing speed and jolting/bouncing. Did I mess up my fuel pump....there was no gas in the spare tank the R tank please help. Thanks